Abstract: A passive-delivery fuel cell system an anode with a fuel flow channel extending along the body and fluidly connecting the inlet to the outlet, wherein a volume of the flow channel per unit length of the anode body increases along the length of the body towards the second end, a capillary check valve in fluid communication with the anode inlet, a vented fuel cartridge in fluid communication with the anode outlet, and a pump in fluid communication with the vented fuel cartridge, the pump configured to pump fuel from the vented fuel cartridge to the inlet.

Abstract: A fluid resistance section outside a fuel cell can regulate the reactant flow against the pressure changes in the reaction zones of the electrodes, reducing the fluctuations in reactant flows to the fuel cell electrodes due to dynamic fluctuations in fluid pressure at the fuel cell electrode because of the release of gaseous products. The outside fluidic resistor can have resistance much higher than the resistance of the flow through the electrodes, thus effectively determining the amount of the reactant flow to the electrodes, independent of the electrode areas.

Abstract: A passive-delivery fuel cell system an anode with a fuel flow channel extending along the body and fluidly connecting the inlet to the outlet, wherein a volume of the flow channel per unit length of the anode body increases along the length of the body towards the second end, a capillary check valve in fluid communication with the anode inlet, a vented fuel cartridge in fluid communication with the anode outlet, and a pump in fluid communication with the vented fuel cartridge, the pump configured to pump fuel from the vented fuel cartridge to the inlet.

Abstract: Methods and systems for regenerating a fuel cell are disclosed, comprising sparging a catholyte liquid with a gaseous oxygen-containing flow stream. In addition, the gaseous byproducts in the catholyte can be collected and then converted to liquid forms for easy disposal. In some embodiments, the regeneration process comprises intermittently regenerating an oxidant flow stream, for example, based on detected conditions. In some embodiments, the regeneration process comprises switching between different modes of oxidant regeneration, for example, based on detected conditions.

Abstract: Methods and systems for regenerating a fuel cell are disclosed, comprising sparging a catholyte liquid with a gaseous oxygen-containing flow stream. In addition, the gaseous byproducts in the catholyte can be collected and then converted to liquid forms for easy disposal. In some embodiments, the regeneration process comprises intermittently regenerating an oxidant flow stream, for example, based on detected conditions. In some embodiments, the regeneration process comprises switching between different modes of oxidant regeneration, for example, based on detected conditions.

Abstract: Methods and systems for regenerating a fuel cell are disclosed, comprising sparging a catholyte liquid with a gaseous oxygen-containing flow stream. In addition, the gaseous byproducts in the catholyte can be collected and then converted to liquid forms for easy disposal. In some embodiments, the regeneration process comprises intermittently regenerating an oxidant flow stream, for example, based on detected conditions. In some embodiments, the regeneration process comprises switching between different modes of oxidant regeneration, for example, based on detected conditions.